A USA -backed, Saudi-led military coalition is fighting against the Houthis on behalf of the government of President Abd Rabbu Mansour al-Hadi, who lives in exile in Riyadh.

Saudi air defences today intercepted a ballistic missile over the southern city of Jizan after being fired from rebel-held territory in neighbouring Yemen, a Saudi-led military coalition said. "We left it in his hands for the time being", Nebenzia told reporters.

If the Saudi-led coalition capture Hudeida, it would effectively be in control of Yemen's most vital lifeline and the main gateway for imports of relief supplies and commercial goods - Hudeida is the point of entry for some 70 percent of Yemen's imports.

The United Arab Emirates has given the UN less than 48 hours to try to negotiate a Houthi ceasefire at the strategic Red Sea port of Hodeidah before it mounts an attack on the port through which the bulk of food, medicine and gas to the rest of Yemen is distributed.

He said the Houthi violations are still going on in the province of Saada, the platform of ballistic missiles and the destination of smuggled missiles from outside Yemen.

Guterres, the United Nations chief, said there has been a recent "lull in the fighting" to allow for discussions and hopefully avoid a battle.

Almost 10,000 people have been killed since the alliance launched its intervention in Yemen in March 2015, contributing to what the United Nations has called the world's worst humanitarian crisis.

"Our top priority is helping to ensure the 22 million Yemenis who need some form of humanitarian aid and protection receive the assistance they need", Grande said last week.

Previous UN efforts have failed to end the war.

Meanwhile, the USA was following developments in Yemen very closely, said Secretary of State Mike Pompeo.

Hodeidah handled 90 percent of the nation's foodstuffs and the humanitarian aid flow before the war, and periodic Saudi blockades of the port since 2015 have heightened fears of starvation and compounded aid agencies' response to a deadly cholera outbreak a year ago.

Impoverished Yemen has been wracked by violence since 2014, when the Shia Houthi group overran much of the country, including capital Sanaa.